Laure Emperaire

Seed exchange networks for agrobiodiversity conservation. A review.

The circulation of seed among farmers is central to agrobiodiversity conservation and dynamics. Agrobiodiversity, the diversity of agricultural systems from genes to varieties and crop species, from farming methods to landscape composition, is part of humanity’s cultural heritage. Whereas agrobiodiversity conservation has received much attention from researchers and policy makers over the last decades, the methods available to study the role of seed exchange networks in preserving crop biodiversity have only recently begun to be considered. In this overview, we present key concepts, methods, and challenges to better understand seed exchange networks so as to improve the chances that traditional crop varieties (landraces) will be preserved and used sustainably around the world. The available literature suggests that there is insufficient knowledge about the social, cultural, and methodological dimensions of environmental change, including how seed exchange networks will cope with changes in climates, socio-economic factors, and family structures that have supported seed exchange systems to date. Methods available to study the role of seed exchange networks in the preservation and adaptation of crop specific and genetic diversity range from meta-analysis to modelling, from participatory approaches to the development of bio-indicators, from genetic to biogeographical studies, from anthropological and ethnographic research to the use of network theory. We advocate a diversity of approaches, so as to foster the creation of robust and policy-relevant knowledge. Open challenges in the study of the role of seed exchange networks in biodiversity conservation include the development of methods to (i) enhance farmers’ participation to decision-making in agro-ecosystems, (ii) integrate ex situ and in situ approaches, (iii) achieve interdisciplinary research collaboration between social and natural scientists, and (iv) use network analysis as a conceptual framework to bridge boundaries among researchers, farmers and policy makers, as well as other stakeholders.

A cidade, um foco de diversidade agrícola no Rio Negro (Amazonas, Brasil)?

As regioes do Medio e Alto Rio Negro, apesar de serem isoladas da malha de comunicacao terrestre e das frentes de colonizacao, caracterizam-se por uma articulacao cada vez mais forte entre a area florestal, a das comunidades, e a urbana, ou seja, as pequenas cidades ribeirinhas. Esta complementaridade, temporaria ou definitiva, se traduz por uma expansao da agricultura periurbana. Propomos uma abordagem comparativa da diversidade agricola entre o urbano e o florestal. Analisamos as relacoes entre formas de manejo dos espacos cultivados (superficies, ciclo de uso e praticas), plantas cultivadas e redes sociais envolvidas no acesso aos recursos fitogeneticos. A analise mostra uma recomposicao dos sistemas agricolas com a permanencia de uma alta diversidade agricola, porem marcada por uma maior vulnerabilidade do sistema em decorrencia da diminuicao do tempo de pousio e da diminuicao da forca de trabalho disponivel. No contexto urbano, as estrategias tradicionais de manejo dos recursos agricolas se combinam a um outro objetivo, o do acesso a terra. A analise aponta para a necessidade de uma reflexao sistemica sobre as possiveis formas de conservacao deste patrimonio biocultural.

Behavioral Plasticity of Triatominae Related to Habitat Selection in Northeast Brazil

Abstract Triatoma pseudomaculata Corrêa and Espínola, 1964 and Triatoma juazeirensis Costa and Felix, 2007 (=T. brasiliensis Neiva, 1911 [part]), are sylvatic vectors of Trypanosoma cruzi (Chagas, 1909), the causative agent of Chagas disease, in northeast Brazil—especially in the caatinga region. In an area of caatinga in the State of Bahia, we compared the wild and peridomestic habitats of these two species of Triatominae to assess their behavioral plasticity in relation to habitat selection in different environments. In the sylvatic environment, the habitat of these two species is never shared. T. pseudomaculata is found in trees and bird nests, but without apparent preference for any particular tree species. In contrast, T. juazeirensis is exclusively rupicolous (found among rocks). Both species invade peridomestic structures but do not display a significant ability to colonize human dwellings. In the peridomestic area, they are highly adaptable to different habitats and can occupy substrates that they do not colonize in the sylvatic environment. This behavioral plasticity seems to be more striking in T. juazeirensis—rupicolous in sylvatic environments but colonizing wooden structures in the peridomicile in >80% of cases.

Dinâmicas das agriculturas amazônicas

O presente trabalho aborda sob varios ângulos as dinâmicas de sistemas agricolas, muitas vezes agrupados sob a denominacao generica de agricultura familiar, sejam essas agriculturas de tipo campesina, tradicional ou indigena. Os instrumentos metodologicos mobilizados nos artigos sao varios: etnografias, biografias, trajetorias coletivas, familiares ou individuais, fontes historicas, levantamentos da agrobiodiversidade, analises geneticas, mas todos tem em comum a caracteristica de entremear leituras do passado e do presente. O objetivo do dossie e propor uma leitura sob varios ângulos das dinâmicas de sistemas agricolas em um contexto marcado por mudancas socioculturais, economicas, ambientais e de politicas publicas que impactam os sistemas locais e ainda pouco abrem caminhos para propostas diferenciadas.